octane

n hydrocarbon compound present in petrol and used as a measure of its quality and efficiency 辛烷.

occupational, occupied, occupier, occupy, occur, occur to, occurrence, ocean, ocean lane, ocean-going, oceanarium, Oceania, oceanic, oceanography, ocelot, ochre (US also ocher), Oct, oct(o)-, octagon, octagonal, octane number (also `octane rating), octave, octavo, octet (also octette), October, octogenarian, octopus, ocular, oculist, odd, odd job man, odd jobs, odd-looking, oddball, oddity, oddly, oddment, oddness, odds, odds-on,